hetsch



4 Sheets-Sheet l Feb. 19, 1929.

- F. K. HETSCH BURNER FOR FURNAcEs FiledvDec. 2, 1926 Feb.19, 1929.1,702,298

F. K. HETSCH BURNER FOR FURNACES Filed Dec. 2, 1926 4 Sheets-Sheet 2 l ll Feb. 19, 1929. 1,702,298

F. K. HETscH BURNER FOR FURNACESl Filed Dec. 2, 1926 4 Sheets-Sheet 3Feb. 19, 1929.

F. K. HETSCH BURNER FOR FURNACES Filed Dec. 2, 1926 4 Sheets-Sheet 4 waMTM. i. w. m, Pw. w .mi B1 I (E til Patented Feb. 19, 1929.

UNITED STATES PATENT OFFICE.

FRANZ KARL HETSCH, OF MANNHEIM, GERMANY.

BURNER FOB, FU'IRJNA'CES.v

Application filed-December 2i, 1926, SerialV No. 152,190, and in GermanyNovember 4, 1925.

My invention relates to a burnerV for fur-` naces. v Y f Y t In manyfurnaces it is desirable to change the fuel used according to whethercoal, oil or gas is the most economical fuel-for the time being.

My invention consists of. a burner which'v permits the supply of fuelgases or liquid or Vpulveriz'ed fuel to the furnace either alternatelyor simultaneously. .In-this way the first cost of the furnace plant andthe space requirement'is considerably reduced and the plant itselfbecomes simpler inoperation as well as in layout. Some embodiments of myinvention are illustrated` in the drawings aXed hereto.

In these drawings: I

Fig. 1, represents a Vlongitudinal section through the improved burner7Fig. 2,- a sectional elevation through the burner casing with theregulating member partly in full view7` .Fig.. 3, a cross-section alongline A-fB of Fig..l,

Fle- 4, a Fig. 1, A-

Figs. 5, 6 land 7 cross-sections through modified constructions of aburner,

Fig. 8, a development of the cam faces Vfor the regulator,v Y

Fig. 9, a diagrammatic representation of the cooperationofthe-distributing edges,l and i F ig.-10,.a diagramshowing thevariations in `the controlled cross-sections.

`cross-section along line C-D of Referring tol Fig., 1y of the drawings,thev tubular inward projection 7. To this pro-V `iection is attached,for instance by threading an extension 8. The tubular projection 7 'isprovided at the top with an opening 44-into which opensthe gas admissionbraneh, see

also Fig. 3Q In thecover Gris journalled a vspindle 9 which is sealedfbya stuilingboxV 10.

Upon theout-er end of the spindle is mounted the control lever '11. Itis equipped Witha nose 12 which runs over a cam surface' 13 cast uponthe cover. I

,E By turning the lever 11 the spindle 9 is not only turned but alsoaxially displaced, due'` to the cani7 against the compression spring 42n'iountedonyspindle 9. To the inner end of Vthe spindle 9 is pinned thehub 14a of a tubufrustoeconical tubular extension 8 on the other handare" formed the passages for the air of combustion and thevfuel. Theillustrations show that posit-ion `of the control lever l V11 in whichthe respective walls forming these passages are farthest apartv and thusthe passage cross-sections are the largest. By

rotating the regulating lever 11 the piston slide is gradually drawnfarther into the casing and thus all passage cross-sections are reducedThe'outer current of air supplied through inlet 2 issues between theWalls 15 and 16. A secondcurrent of air enters-the .furnace through anannular channel or port .tion shown in Figs. 1 and 2 with the edge offixed ring 4. Vrlhe width ofthis port is varied during theabove-mentioned longitudinal motion ofslide 14 when the lfront `edge ofkthe ring graduallyv closes this port. The-main air current is controlledby the position of edges 17 and18 and Whenentering the mouth it forms anannular inner jet. The helical spring 42 abuts against the stuiiiiig boX10 and presses against the hub 14- so that the nose 12 of the controllever 11 is permanently kept in contact with the control cam 13. c

The fue] Agas entering through the inlet 3 flows through the interiorofthe inner tubular easing 7, 8 and is controlled by the annu-Vlarxedges 2S'and 24.Vr The oilinlets 5 in the casing open into anannular groove 19 opposite which are, located the radial bores 25 in thecontrol slide. As Fig. 2 shows these bores lare.staggered in relationtov one' another so .that they are closed or opened in succession ,bythe longitudinal'regulating motion of the slide piston 14. At both sidesof these bores t.

packing or sealing grooves 26, 27, Q8, Q9 with radial drain openings 30are provided through which leakage oil is conducted into the inain aircurrent. In this Way dripping of theljurne'r iseilectively zrvoided. Thesealing grooves-QG, 2T, 2S and 29 remain in any regulating positioncovered hy the cylindrical Wall surface of the ring 4i within the burnerbody. They neither issue at the two ends of this ring nor do they comein direct con'iniunication with the oil supply groove 1S), when theslide is' operated.

instead of fuel gas a con'ihustihle powder whirled up by air mayhelilouin into the gas adruissionl hranclr 3. for instance pulvcrizcdcoal or sawdust. Oil and gas or oiland pulverized coal may even heemployed silnulfarneously. lThe distributing or control edges are sosl'iafped that at the end they merge into the c i'flindrical shsrpe asclosely as possil'ile such as the edges l5. 'l0 and 2B' as Well as 2lishoiv particularllyv clearly. ln this wry the air and the fuel attain anaxial direction of flow for the purpose of lfiringing aflmut a uniforinmixture. The hclicall'y shaped rihs 2l and S221, inrpart a rotary motiontol the central and the" main air ciiirrent as irell as to theenterii'i'g gaslcirrreiit. Between the indii-"idual gyratin'g airci'irrents passing between these vanos iwacuated spaces are fornredsothat in thepcasc of ope 'ation with the gaseous fuel and in the caseof operation with oil the central cru-rent of airis suc-lied into thespaces. This resl'ilts a particularly uniform mixture and whirlingthrough of the fuel and the cornlmstion air.

ln the burner according to iny invention the control cainsurfacue 13 andthe distribution edges/115g 18 and Q3 are so shaped that at sinalloutputs' a very line adjust-ment is possihle. for larger outputs on the.other hand a Wide r-igulation range with coarse adjustments isattainable.

in Fig. S'of thedrawings the controlling cani siirface shown developedwith refer- `ence to thc niodilication Figs. l to 4. 'for e1:-

a'inph. For small oiitputs the gradient of the curve face is less. asangle A. showsa and. for larger outputs the gradient is steeper. as:ingle lil shows. `'Both angles of inclination A. and B are prcforahlylocated Within the angle of friction for the particular nnltcrial usedso that the parts reinain automatically in adjusted` position. Smallnotches 43 may he provided for in't ;:i'i1`1ediate positions. 'Vhile thenose l2 slides along the cani portion of the lesser gradient the spindleis axially displaced by theldistance c. A; similar distance isconseqiiently also traversed inthe saine direction hy the distrihutingedges of the slide. The` distributing edge m in Fig. 9', which inigltrepresent for instance edge 17 in Fig. 1, thus reaches the position m1,when the lesser grade earn portion a has been traverscd. The stationaryedge 18 is inclined loy the angle Al. In thesecond steeper part Z) ofthe Cain control the controlling edges traverse an approximately equallylong axial path d. The controlling edge thus reaches the position m2.The crossesection then opens considerably more inasmuch as thestationarv edge is here inclined at the larger angle Bil. In Fig. l` ofthe drawings the size of the discharge cross-section is graphicallyillustrated7 the broken line I indicating the sinn' of the regulatedair` discharge cross-sections, the line II the suin of the gas dischargecross-sections and Hl the sinn of the oil discharge cross-sections. Thegraphic reiiuesentatioir shows that the control elements adjusts allfuel and air outlet cross-sec` tions simultaneously for each unit oflength traversed in axial direction and effects the supply of fuel andcombustion air iniXed in the correct proportion74 so that a regulatingrange of to 100% is possible and a particularly line a d j ustnn-nt isobtained for small outputs. By this .fine adj ustinent ofthe co1nhustion the operation of the furnace is iinproveds the consumption offuel reduced and the economy of the service increased.

The burner operates satisfactorily with air pressure corresponding toa100 nun. Water cohunn or with a steam pressure of `0.2 atmospheres. Thegas pressure required amounts to nun. Water column and may be higher.rthe internal stuiiing hoX l0 shown in Figs. l and 2 prevents the escapeof the gas to the outside. Preferably the gas and the air pressureshould he adjusted at di iiereut values. In the case of inferior gasesthe gas may he introduced through the intal'ze of larger diameter 2 andthe air through the intake of smaller diameter 3 in order to avoidhigher gas pressures otherwise necessary.

llfhen standard fuel oil is employed a useful` oil pressure of 500 nun.Water column is quite sufiicient. These low Working pressuresfor theatoiniZing agent and theV fuel facilitate the sealing of the pipe-linesand reduce the auxiliary power requirement necessary for operatingI thefurnace. The rapid Wear and tear forniingan objectionable feature ofhiglrpressiufe atoinizingnozzles is also efl'cctirely avoided. Y

The Mouthpieces of the nozzles with their controlling or disirihutingedges are dcinouutahlo involving, as Fig. l shows thc controlling edgesl?, l0, i8 and Q?) hy way of exrunple, so that the nozzle areas may heeasily and quickly adapted for different pressures or heating values ofthe gi or for different pressures ofthe atoniizing niedirun at low airpressure or low steain pressure.

lf oil only is employed the central part of the burner enclosed -by thetutelar ertension 7? 8 may also he utilized for the supply of thecombustion air. This may he effet-ted in a. simple manner lay turningthe casing 2 through angangle of 180o in relation to the cover 6 and itsinward extension. rlhis is illustrated in Fig. of the drawings; Theinner discharge end of intake?) which in Figs. 1, 2 and 3 is shown toregister with intake port 44 of the inner tubular member 7` is thenloca-ted on the side opposite from port 141, whereas the latter port nowreceives combustion air entering through the intake 2 whichnow registerswith port i-leso that' this air now passesthrough the interior of thetubular .extensions 7 and 8. The gas in- -take 3 then remains closedtowards the outside and may be omitted altogether, as illustiatedninFig. 7 i of the drawings, lin which casing 1 is shown again turnedint-he same position as shown in Figs. 1 'and 2j In the embodiment of myinvention illustrated in Fig. 5 furthcrprovisions are made to preventt-lie burner from dripping. j For this purpose a ring L10 is providedwithin the casing or shell ofthe burner Awhich on the air supply side ofthe casing, in the illustrated relative position ofthe parts in Fig.

5 the upper side, is provided with a port 405, y

i into the inner air jet, however, through a port 2O and partof it, orat times all of it, may be drainedl off through oil discharge openingal.

'Through this opening 41 are also discharged the quantities of oil whichaccumulates in the interior of the burner in case the air blower shouldaccidentally stop, for instance due to thebreaking of the driving beltyor failure ofthe electric power supply, which oil would otherwise flowinto the hot `combustion chain-- bei' where it might lead to anexplosion. lf!

the oil' issuing from the outlet/l1 is 'discharged through a. syplionnot shown here the risk of an explosion is entirely eliminated.

in 5 thehandregulator is shownv with a hol-low spindle "39. Such aspindle may be employed in allmodifications and serves Y for theintroduction of a gas ignition flame or an electric igniter whichignites the coinbustible mixture directly in front of the mouth of theburner. In this Way not only the starting of the furnace is facilitated,but also an increased operation reliability is obtained. i

In some instances it not necessary, as shown in Figs. land 2, tovmaketlie exten-` sion 8 of the inner fixed tubular member 7 as aseparate element, threaded onto mein-v ber 7 It may also be madeintegralthere- 'i vwith as is shown inFi/g.l 6.

Y 'Various modifications and changes `may be jinade without departingfrom the spirit and v the scope of the invention, and I desire,therefore, that only such limitations shall be placed thereon as areimposed by the prior art. i i I claim as my invention v 1. A burnercomprising in combination a tubular casing open at one end and having acover at the other `end, a gaseous fuelinlet andan air inlet on saidrcasing, a guide ring fined concentiically within said casing and boresthrough said ring and casing for liquid fuel admission tothe interiorthereof, anA

inner tubular elementV extending coaxially with said casing frointhecasing cover and havingan intake opening adjustable in line with saidgaseousfuel inlet, a spindle in said extension .journalled slidably androtatably in the casing cover in axial alinement therewith, a rotarypiston .slide fixed upon the free end ofsaid spindle and disposedbetween said ring and said tubular extension, the outer end of saidslide forming an annular nozzle with the mouth of the casing andpermitting the issue of aportion of the con'ibustion air therethrough, aport in said slide controlled by said` ring at the axial slide motionfor supplying another portion of the combustion;

air tothe inside of the slide to issue at its mouth, the rear slide endforming an annular Vport with an outside portion of said fixed tubularextension for cont-rolling the passage of the remainderof the combustionair be'- tween'saidextension andthe slide tothe ini terior of the slideby the axial slide motion, said slide having perforations on itscircumference registerable with said liquid fuel boresin said ring whenthe slide is axially shifted to supply liquid fuel to the remainder ahub on said slide forming anannular port with the free eiidof saidtubular extension for controlling by the axial slide motion the gaseousfuel Adelivery from said tubular extension to the slide mouth, and meanson the outer end of said spindle for rotating and axially displacingsaid slide.

2. ,A burner comprising in combination a ktubular casino` oben at oneend and havin a cover at the other end,a gaseous fuel inlet and an airinlet on said casing, a guide ring fixed concentrically within saidcasing and bores through said ring andvcasing for liquid fueladii'iission to the interior thereof, an inner tubular element extendingcoaxially with said casing from the casing cover and having an intake.opening adgustable inline with the casing cover in axialalinen'ientthereuf'ith, a rotary piston slide fixed upon the. free endof said-spindle and disposed between saiduring :and said rtubularextension, the

louter endof said slide` forming an annular nozzle. with the mouth ofthecasing and permitting theissue of a portionpofthe coinioo of thecombustion air to be atomized by it,

Vsaid gaseousifuel inlet, a spindle insaid exl tension journalledslidably and rotatably in hustion air therethrough, a port in said slideControlled hy said ring` at the axial slide inotiontor supplyinganotherportion ot the Combustion air to the inside of the slide to issue at itsmouth, the rear slide end forming au annular port with an outsideportion ot' said fixed tubular extension for controlling the passage otthe remainder ot the Cornhustion air between said extension and theslide to the interior oit the slide la' the axial slide motion, saidslide haif'ing p `riliorations on its eirciunl'orenee registerahle withsaid liquid 'fuel hores in said ring); when the slide is axially shiftedto supply liquid iuel to the remainder ot the eou'ihustion air to heatomized hy it, a huh on said slide 'forming an annular port with thefree end ot said tubular extension 'for Controlling luy the axial slidemotion the gaaf-zeur: 'Fuel delivery troni said tubular extension to theslide mouth, a lever on the outer end ot' said spindle tor rotating` it.and a suitably stepped earn on the outside ot the easing; eovercooperating with said lever to axially vdisplace said spindle when thelever is rotal'ied7 t-o control said slide ports, and liquid `tuelsupply t'oi` obtaining,` the desired air and `fuel proportions for dit'-lierent burner outputs.

3. A burner comprisingl in combination a tubular easing open at one endand having a cover at the other end, a gaseous fuel inlet and an airinlet on said Casing, a fluide rino; lined eoneentrieally Within saideasing' and horesthrough said ring and casing tor liquid 'fuel admissionto the interior thereof, an inner tubular element extending` eoaxiallywith said easing` from the casingeover and having an intake operolng,adjustable in line with said gaseous tuel inlet, a spindle in saidextension journalled slidahly and rotatably in the easing' cover inaxial alineinent therewith, a rotary piston slide fixed upon the :treeend ot said spindle and disposed lieti'veen said ring and said tubulareXtension.,`

the outer end ot said slide 'orn'iing an annular nozzle with the mouthoi the easing and perinitting` he issue oit a portion of the eoinhustiou air theretlu'ough, a port in said slide controlled hy said ring'at the axial slide motion ior supplying another portion the eonlliustiouair to the inside et the slide to issue at its mouth, the rear slide endtorlniiu;` an annular port with an outside portion oit said lixedtul'mhir extension Ytor controlling the passage ot the remainder et theeernloustion air between said extension and the slide to the interioroill the slide loy the axial slide motion` said slide havingperforationson its eirmun'lferenee roggistorahle with said liquid fuel hores in saidring' when the slide is aXiaL ly shifted to supply liquid ituel to theremainder ot' the combustion air to loe atoinized by it7 a huh on saidslide forming au annular port with the tree end oli' said tubularextension for controlling hy the axial slide niotion the gaseous fueldelivery from said tubular .extension to the slide mouth, a coinpressionspring on said spindle bearing at one end against said slide huh and atthe other end against the easing Cover, tending to nieve the slideforward, a lever at the outer end ot said spindle for rotating it and asuitahly stepped cani on the outside of the easing oever cooperatingWith said lever to axially dispiace said spindle against the torce otsaid spring when said lever is rotated.

fi. A burner Cou'iprisingl in Combination a tuluilar casing open at oneend and having a cover at the other end, a gaseous tuel inlet and an airinlet on said easing, a guide ring fixed eoneentrieally Within saideasing and hores through said ring and easing for liquid 'fuel admissionto the interior thereof, an

inner tubular element extending coaxially' with said easing troni theeasing cover and having an intake opening adjustable in line with saidgaseous fuel inlet. a spindle in said extension journalled slidahly androtatably in the easing; oever :in axial alineii'ient therewith, arotary piston slide fixed upon the tree end oit said spindle anddisposed between said ring and said tuluilarextension, the outer end oisaid slide forming an annular nozzle with the mouth of the casing andpermitting the issue of a portion of the combustion air tlierothrough7 aport in said slide controlled hi', l

J e ing at the axial slide motion for supplying,=` another portion'otthe combustion air to the inside ot the slide to issue at its inouth,the rear slide end formingl an annular port with an outside portion ofsaid fixed tubular extension for controlling` the passage ot theremainder of the eonihustion air between said extension and the slide tothe interior of the slide hy the axial slide motion, said slide having;pertorations on its circuniterenoe staggered in a plurality oftransverse planes through the slide, said pertorations beingregister-aille with said liquid fuel hores in said ring;- When the slideis axially shifted to supply liquid fuel to the remainder' ot theoonihustion air to he atoniized by it, a huh on said slide vformingI anannular' port with the tree end ot said tuhul ar extension iorcontrolllnn hy the axial slide motion the gaseous iluel deliyery tromsaid tubular extension to the slide mouth, and means on the outer end otsaid spindle tor rotatinul and axially displaeiug said slide.

A burner Cornprisingy in combination a tuhular easing` open at one endand havingl a rover at the other end` a gaseous i'uel inlet and an airinlet on said easing, a guide rin;r titte-d Coneentrieally Within saideasing` and hores through said ring; and easing tor liquid fueladmission to the interior thereof, an inner tubular element extendingCoaxially with said easing from the easing Cover and having; an intakeopening adjustable in line with said gaseous tuoi inlet, a spindle insaid extension journalled slidably and rotatablyV in the casing cover inaxialalinement therewith, arotary piston slide fixed upon the free endof said spindle and disposed betweensaid ring and said tubularextension, the outer end of said slide forming an annular nozzle 'withthe mouth of the casing and permitting the issue of a portion ofthecombustion air'therethrough, a port lin Vsaid slide controlled by saidring at the axial slide motion for supplying another portionl of thecombustion air to the inside of the slide to issue atits mouth, the rearslide end forming an annular port with an outside portionof said fixedtubular extension for controlling the passage of the remainder of thecombustion air between said extensionl and the slide to theinterior ofthe slide by t-he axial slide motion, said fixed casingring havingl anannular recess at its inner periphery in which the aforementioned.liquid fuel supply-bores terminate, saidA slide having radialperforations on its circumference staggered ina plurality of transverseplanes through theslide, so that they can be gradually brought into andout of register withvsaid annular recess when the slide is' laxiallyshifted for variably supplying` liquid 'fuel to said remainder of thecombustion-air Y extension for controlling by the axial slide motion thegaseous fuel delivery from said tubular extensionto the slide mouth, alever on the outer end of said spindle for rotating.

it, and a suitably stepped cam on the outside ofthe casing covercooperating` with said lever to'axially displace said spindle when thelever is rotated, to control said slide ports and liquid fuel supply forobtaining the desired air and fuel proportions for different burneroutputs. l y

6. Aburner comprising in combination a tubular casing open at one endand having a cover at the other end, a gaseous fuel inlet and an airinlet on said casing, aguide ring fixed concentrically within saidcasing and bores through said ring and casing for liquid fuel admissionto the interior thereof, an inner tubular-element-extending coaxiallywith said casing from the casing'cover and having an intake openingadjustablein line with said gaseous fuel inlet, a spindle insaidextension journalled slidably and rotatably in the casing cover inaxial alinement therewith, a rotary piston slide fixed upon the free endof said spindle'and disposed between said ring Y and said tubularextension, the outer end of said slide forming an annular nozzle withthe through, a port in said slide controlled by said ring at the axialslide motion for supplying another portion of the combustion air to theinside of the slide to issue at its mouth, the

rear slide end forming an annular port with an outside portion of saidfixed tubular'extension for controlling the passagev of the remainder ofthe combustion air between said extension and the slide to the interiorof the slide by the axial slide motion, said slide having perforationson itscircuniference registerabie withsaid liquid fuel bores in saidring when the slide is axially shifted to supply liquid fuel to theremainder of the V'combustion air to be atoinized by it, a hub on saidslide forniing an annular port with the free'end of said tubularextension for controlling by the axial slide motion the gaseous fueldelivery from said tubular extension to the slide mouth, and means onthe'outer end of saidspindle for rotating and axially displacing saidslide, the mouth portion of said casing, said slide and szid innertubular extension being detacha e. 1 f

7. A burner comprising in combination aA tubular casing open at one endand having a cover at the other end, an air inlet on said cas ing, aring fixed concentrically within said casing and bores through said ringand Casing for liquid fuel admission to the interior thereof, an innertubular extension element extending coaxially with said casing from saidcover, a spindle in said extension disposed slidably rotatably in thecover in axial alinement therewith, a rotary piston slide fixed upon theiiinei end of said spindle and disposed between said ring 'and saidtubular extension, the outer end of said slide forming an annular nozzlewith the casing'niouth and permitting the issue of a portion ofthecombustion air therethrough, a port in said slide controlled by saidring at the axial slide ino-v tion for supplying another portion of thecombustion air to the inside of the slide to issue at its mouth, therear slide end forming an annular port-with an outside 4portion of saidfixed tubularV extension for controiling the supply of a third portionof combustion air from said inlet between said extension and the slideto the slide interior, said slide having perforations on itscircumference registerable with said liquid fuel bores in'said fixedring when said slide is axially shifted to supply liquid fuel to saidthird portion of combustion fuel bores, said two sets of ribs impartinga having ports for controlling the air-fuel whirling motion to the fuelair mixture passmixture for the burner, said element having 10 ingthrough the burner. l an intake port leading to its interior, and bell.Aburner having,- a easing provided with iiigrotatably disposed to permitthe connecan air intake, a fuel intake and a liquid fuel tion of saidport Wit-lisaid air intake or said intake, a tubulai element extendingfrom the gas intake at will. rear Casing end into the interior thereof,and ln testimony whereof I aflix my signature. a slide between thecasing and said element FRANZ KARL HETSCH.

